Trump has repeatedly claimed a vote for Ms Clinton is a vote for the TPP.

"She supports the Trans-Pacific Partnership - not now but very soon if she wins and we can't let her win," he said earlier this week when releasing details of his own economic policy.

Ms Clinton says her jobs and tax plans will better help middle-class Americans than Trump's.

"He's offered no credible plans to address what working families are up against today," Clinton said, shortly after touring Futuramic, a hangar-like, high-tech factory in Warren, Michigan, that makes parts for the aerospace industry.

Workers' anxiety over trade deals has become a central theme in the 2016 election, and Ms Clinton rejected the portrait Trump has painted that she is only pretending not to favour the TPP, a planned deal which she had praised when she was Secretary of State in President Barack Obama's first term but has opposed as a candidate for the presidency.

Ms Clinton had also previously supported the North American Free Trade Agreement, which was signed by former US President Bill Clinton, her husband, and which Trump routinely disparages as bad for American jobs. Ms Clinton now says she would renegotiate it.